(1. 齐鲁工业大学(山东省科学院) 生物基材料与绿色造纸国家重点实验室,济南 250353;
2. 齐鲁工业大学(山东省科学院) 制浆造纸科学与技术教育部重点实验室,济南 250353;
3. 山东省科学院 新材料研究所,济南 250014)
摘 要: 锂硫电池具有较高的理论比容量(1675 mA·h/g)和能量密度(2600 W·h/kg),被认为是最具发展前景的高能量密度储能电池系统之一。然而该体系还有一些问题尚未解决,如活性物质硫的导电率过低、多硫化物溶于电解液造成的穿梭效应和活性物质损失以及脱/嵌锂过程中发生的体积膨胀等,会导致电池库伦效率低、循环性能差和容量衰减快,严重阻碍锂硫电池的商业化应用。近年来,天然生物质碳材料因高导电性、大比表面积、异质元素掺杂、价格低廉等优势,作为包覆硫基体广泛应用于锂硫电池正极材料中,可极大地提高硫的利用率,抑制穿梭效应。本文系统总结了不同来源天然生物质碳材料的合成、优化以及作为硫载体的应用进展,并对其未来的发展前景做出展望。
关键字: 生物质;碳材料;锂硫电池;正极材料;多孔结构
(1. State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shangdong Academy of Sciences), Jinan 250353, China;
2. Key Lab of Pulp and Paper Science & Technology, Ministry of Education, Qilu University of Technology (Shangdong Academy of Sciences), Jinan 250353, China;
3. Advanced Materials Institute, Shandong Academy of Sciences, Jinan 250014, China)
Abstract:Lithium-sulfur (Li-S) batteries exhibit high theoretical specific capacity (1675 mA·h/g) and energy density (2600 W·h/kg), thus they are regarded as one of the most promising high energy density storage systems. In spite of these significant advantages, there are several problems and challenges that have to be solved for Li-S batteries. For example, the low electrical conductivity of sulfur, shuttle effect and loss of active substances caused by the polysulfide dissolved in electrolyte, and the volume expansion during the delithium/lithium intercalation reaction, directly lead to low coulombic efficiency, poor cyclical stability, rapid capacity decay, which seriously hinder the commercialization of Li-S batteries. In recent years, natural biomass-derived carbon materials, as sulphur-coated materials, have been widely used as cathode materials, showing excellent electrochemical performance. Their natural advantages of high conductivity, large specific surface area, heterogeneous element doping and low price can greatly improve the utilization rate of sulfur and inhibit the shuttle effect of polysulfide. This paper systematically summarizes the synthesis and optimization of natural biomass-derived carbon materials from diverse sources, and their applications as the hosts for storing sulfur. Moreover, the future research direction of electrode materials is prospected.
Key words: biomass; carbon materials; lithium-sulfur battery; cathode material; porous structure